The enriched environment mice recovered long term memories while mice kept in a bare cage on their own did not.
Now, articles about health will probably advise retirees to take university extension courses and regular exercise to preserve memory and cognitive function but it occurs to me that the real advantage of the "enriched environment" for those mousies was that it was simply more fun than a bare cage.
Thinking about a biological necessity to having fun put me to mind a seminar given by Len Syme that I attended a couple of years ago where he talked about the Whitehall Study of British Civil Servants. Now, this study found what all the lefty sort of public health people always talk about, the health risks associated with disparities of wealth and power. But what Dr. Syme talked to us about was something a bit deeper - the real health disparities lie in the ability (or not) for self determination.
From a 1998 interview:
Len Syme:... those at step 2, one step from the top, professionals and executives in the British Civil Service, doctors and lawyers, have rates twice as high as those at the very top.
Norman Swan: So that there's a very sharp increase.
Len Syme: Oh yes, it's dramatic. Why people at the bottom have higher rates (of mortality), we all think we understand it. We talk about low income, low education, poor medical care, poor housing, but that is not true of professionals and executives. My first assumption was that that was a unique observation among British Civil Servants in London. We did a review of the world's literature on this, and it turns out it's a universal observation; in all of the industrialised world for virtually every disease we know about there is a step-wise gradient.
The most interesting part of the British Civil Service study is that the first thing Marmot and his group did was try to explain this gradient by reference to the important risk factors that we know about. He adjusted for diet and for smoking and for blood pressure and for physical activity and obesity and social support, and hundreds of other variables. And the fact that there's a gradient is true in spite of the fact that you adjust for all these factors. So those factors explain something like 25% - 35% of the gradient, but the rest is unexplained by those factors.
So that's why I put social support aside as the explanation. Clearly it's involved, but I'm looking for the answer and that is not the answer. My hypothesis is that it's control of destiny. And what I mean by that is that the lower down you are in social class standing, the less opportunity and training you have to influence the events that impinge on your life.
Norman Swan: This is the notion that it's not the high powered executive sitting on phones and jumping on jets to Paris and London who drops dead, it's actually the person below that person, who has been told what to do, has very little chance to decide how they do their work; they've been told what to do, they're given the time line, and they've got very little latitude, and they're just spinning out of control and often at home the same thing's occurring.
Len Syme: Exactly. There are two streams of research that support that idea. One is work by an American, one a Swede, on what they call 'demand latitude'. And what they find is that people who have very high demands at work and very little latitude in discretion for dealing with those demands, have the very highest rates of disease, and that's exactly what we found in the British Civil Service.
I went to each of the British Civil Service agencies, to the personnel directors, and examined all the jobs in terms of the demand in latitude, and that's clearly what's going on.
The second thread of evidence however, is even more dramatic. As I said, Marmot has looked at several hundred factors to explain the gradient, without success. Maybe for 10, 15 years he's been trying as hard as he can, looking at things ranging from fibrinogen to whether you have a car, without success. But in July of 1997 there's a paper in 'Lancet' where he, for the first time, controls this gradient for the concept of control.
Norman Swan: And?
Len Syme: The gradient disappears.
Norman Swan: So that becomes the key factor?
Len Syme: In fact, 'Lancet' asked me to write a commentary; and my argument was this is the most important finding in the last several decades.
One day researchers will will prove beyond a shadow of a doubt that people need their fun, and that people need to be free, that life depends on liberty and the pursuit of happiness.
So don't let anyone steal your bucket! You're under doctor's orders to hold on to it.